using System;
using System.IO;

using iTextSharp.text;

/*
 * $Id: PdfIndirectObject.cs 106 2009-12-07 12:23:50Z psoares33 $
 * 
 *
 * This file is part of the iText project.
 * Copyright (c) 1998-2009 1T3XT BVBA
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
 * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * you must retain the producer line in every PDF that is created or manipulated
 * using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */

namespace iTextSharp.text.pdf {
/**
 * <CODE>PdfIndirectObject</CODE> is the Pdf indirect object.
 * <P>
 * An <I>indirect object</I> is an object that has been labeled so that it can be referenced by
 * other objects. Any type of <CODE>PdfObject</CODE> may be labeled as an indirect object.<BR>
 * An indirect object consists of an object identifier, a direct object, and the <B>endobj</B>
 * keyword. The <I>object identifier</I> consists of an integer <I>object number</I>, an integer
 * <I>generation number</I>, and the <B>obj</B> keyword.<BR>
 * This object is described in the 'Portable Document Format Reference Manual version 1.3'
 * section 4.10 (page 53).
 *
 * @see        PdfObject
 * @see        PdfIndirectReference
 */

public class PdfIndirectObject {
    
        // membervariables
        
    /** The object number */
        protected int number;
        
    /** the generation number */
        protected int generation = 0;
        
        internal static byte[] STARTOBJ = DocWriter.GetISOBytes(" obj\n");
        internal static byte[] ENDOBJ = DocWriter.GetISOBytes("\nendobj\n");
        internal static int SIZEOBJ = STARTOBJ.Length + ENDOBJ.Length;
        internal PdfObject objecti;
        internal PdfWriter writer;
        
        // constructors
        
    /**
    * Constructs a <CODE>PdfIndirectObject</CODE>.
    *
    * @param        number            the objecti number
    * @param        objecti            the direct objecti
    */
        
        internal PdfIndirectObject(int number, PdfObject objecti, PdfWriter writer) : this(number, 0, objecti, writer) {
        }
        
        internal PdfIndirectObject(PdfIndirectReference refi, PdfObject objecti, PdfWriter writer) : this(refi.Number,refi.Generation,objecti,writer) {
        }
    /**
    * Constructs a <CODE>PdfIndirectObject</CODE>.
    *
    * @param        number            the objecti number
    * @param        generation        the generation number
    * @param        objecti            the direct objecti
    */
        
        internal PdfIndirectObject(int number, int generation, PdfObject objecti, PdfWriter writer) {
            this.writer = writer;
            this.number = number;
            this.generation = generation;
            this.objecti = objecti;
            PdfEncryption crypto = null;
            if (writer != null)
                crypto = writer.Encryption;
            if (crypto != null) {
                crypto.SetHashKey(number, generation);
            }
        }
        
        // methods
        
    /**
    * Returns a <CODE>PdfIndirectReference</CODE> to this <CODE>PdfIndirectObject</CODE>.
    *
    * @return        a <CODE>PdfIndirectReference</CODE>
    */
        
        public PdfIndirectReference IndirectReference {
            get {
                return new PdfIndirectReference(objecti.Type, number, generation);
            }
        }
        
    /**
    * Writes eficiently to a stream
    *
    * @param os the stream to write to
    * @throws IOException on write error
    */
        internal void WriteTo(Stream os) {
            byte[] tmp = DocWriter.GetISOBytes(number.ToString());
            os.Write(tmp, 0, tmp.Length);
            os.WriteByte((byte)' ');
            tmp = DocWriter.GetISOBytes(generation.ToString());
            os.Write(tmp, 0, tmp.Length);
            os.Write(STARTOBJ, 0, STARTOBJ.Length);
            objecti.ToPdf(writer, os);
            os.Write(ENDOBJ, 0, ENDOBJ.Length);
        }
    }
}
